Hydraulic press



1970 M. c. LUCKY 3,523,444

VENTOR.

BY 5 M W? ATI'OR/VE VJ Aug. 11, 1970 Filed Jan. 5, 1968 LUCKY HYDRAULIC PRESS 5 Sheets-Sheet 4 /Y/ 1 I *4,M L

I! i 1 l a! -l I w Mag/v0. (T lucky INVENTOR.

ATTORNEKJ' 5 Sheets-Sheet 5 M. C. LUCKY HYDRAULIC PRESS Aug. 11, 1970 Filed Jan. 5, 1968 I VENTOR.

A TTO/P/VfKJ' Maa/vre D ("Q lac/4y United States Patent 3,523,444 HYDRAULIC PRESS Maurice C. Lucky, Houston, Tex., assignor to Cameron Iron Works, Inc., Houston, Tex. Filed Jan. 5, 1968, Ser. No. 696,064 Int. Cl. B21j 9/12 US. Cl. 72-453 10 Claims ABSTRACT OF THE DISCLOSURE A hydraulic press comprising a frame, a first platen fixed to the frame, and a second platen mounted on the frame for movement toward and away from the first platen. First and second sets of cylinders are arranged on dilferent levels between the inner faces of the platens, with all the cylinders being perpendicular to the inner platen faces and parallel to one another. The cylinders in each set are arranged in substantially parallel, longitudinally and laterally extending rows, with the rows of one set being parallel to and offset with respect to the rows of the other set, respectively. A ram is sealably slidable within each cylinder, and a means is provided for introducing hydraulic fluid into each cylinder so as to move the ram therein from a retracted to an extended position with respect to the cylinder. Rods extend parallel to the cylinders for transmitting the force developed in the cylinders of the first set to one of the platens and the force developed in the cylinders of the second set to the other platen. When the rams are retracted, the outer ends of the cylinders of the two sets are spaced from one another a distance at least equal to the stroke of each ram from retracted to extended position.

This invention relates generally to hydraulic presses. More particularly, it relates to improvements in hydraulic presses of the type having a plurality of rams for moving one of the platens thereof relative to another platen.

'In conventional hydraulic presses of this type, cylinders for the rams are arranged between the inner faces of fixed and movable platens, so that the die or other work-forming part of the movable platen can be pressed against the work supported on another platen. In the interest of maintaining the length and width of the platens as small as possible, and thus reducing to a minimum the size and cost of the press, each cylinder is normally disposed as close as possible to adjacent cylinders. Even so, of course, the axes of adjacent cylinders are spaced from one another a distance at least as great as the sum of their outer radii.

Thus, according to conventional practices, large capacity presses require more, or larger, ram cylinders and larger platens, even though the increased working area on the platens is not needed. This greatly increases the cost of the press since its frame must be made stronger to withstand the increased bending moments across the platens and the ends of the frames. Consequently, there is a need for a press having a ram arrangement which enables an increased power capacity without the need for the correspondingly larger platens heretofore thought necessary.

Perony Pat. No. 2,197,441 shows a hydraulic press in which the cylinders are arranged in laterally and longitudinally extending rows, with alternate cylinders of one row exteding outwardly from the inner face of one platen and the remaining cylinders of the row extending outwardly from the inner face of the other platen to permit adjacent cylinders in such row to be spaced apart a distance less than the sum of their outer radii. Thus, Perony makes it possible to arrange more ram cylinders within a given area outside the platen faces than can be arranged between the faces of conventional platens.

Patented Aug. 11, 1970 However, as will be apparent from the Perony patent, the working area between the inner faces of the platens is severely limited by the rods which extend from the ram in each cylinder extending from one platen to connection with the other platen. Consequently, there is a limitation on the size and shape of the die or other working forming part which may be disposed between the platens; or, conversely, Peronys platens must be made large to accommodate the work, thereby defeating the objective of reducing the size of the press. Furthermore, and as will also be apparent from the Perony patent, the pressure responsive area of the rams must be relatively small because of the rods, so that the alleged advantage of increased power capability per unit of working area is questionable.

An object of this invention is to provide a hydraulic press having a ram arrangement which enables greater power capacity per unit of platen area than the abovementioned conventional presses, but which nevertheless provides little or no obstruction to the working area between the platens.

A more particular object is to provide such a ram arrangement in which the rams in cylinders of adjacent rows maybe spaced apart a distance less than the sum of their radii.

A further object is to provide such a ram arrangement in which the loads thereon are substantially evenly distributed between the various rams and cylinders.

These and other objects are accomplished, in accordance with the illustrated embodiments of the invention, by a hydraulic press comprising a frame having upright sides and upper and lower ends which form a loop. 'Fixed platens are mounted within the loop at the upper and lower ends of the frame, and an intermediate platen is mounted Within the loop for vertical movement with respect to the frame and the fixed platens. More particularly, a novel arrangement of hydraulic rams is disposed between inner faces of the one fixed platen and the movable platen so as to move the latter toward work supported on the other fixed platen.

First and second sets of cylinders for the rams are arranged on different levels between the inner faces of the platens and with their axes perpendicular to such faces and parallel to one another. The cylinders of each set are arranged in substantially parallel, longitudinally and laterally extending rows, and the rows of each set are laterally and longitudinally offset or staggered, respectively, with respect to those of the other set.

Means including rods extend parallel to the cylinders for transmitting the force developed in the cylinders of the first set to one of the platens and the force developed in the cylinders of the second set to the other platen. With the rams in the cylinders in retracted positions relative to their respective cylinders, the cylinders of the two sets are spaced apart a distance at least equal to the stroke of each ram from such retracted position to extended position. Thus, the rams may be extended so as to move the second platen away from the first platen.

:In the preferred embodiments of the invention, the rods are of lesser cross-sectional area than the rams so that the axis of each ram of each set of cylinders may be spaced from the axes of diagonally opposed rams of the other set by a distance less than the sum of the radii of such rams. Further, and in the interest of an even more compact arrangement of the rams, adjacent cylinders in each set of the preferred embodiment are substantially tangent. Thus, the press of this invention has considerably greater power potential for a given working area than a press having the rams arranged in a conventional manner. At the same time, since the rams are arranged between the inner faces of the movable platen and one of the fixed platens, the opposite face of the J movable platen is free from obstruction which would limit the working space between it and the other fixed platen.

According to one embodiment of the invention, the cylinders of one set extend from one platen and the cylinders of the other set extend from the other platen, and all rods extend from the outer ends of the rams. In an alternative embodiment of the invention, the open ends of both sets of cylinders face toward one platen, and the rods for transmitting the force developed in one set of cylinders extend from the rams in such cylinders, while the rods for transmitting the force developed in the other set of cylinders extend instead from the closed ends of such cylinders.

The rods for transmitting the force developed in the cylinders of one set may extend past the cylinders of the other set for transmitting such force directly to one platen, as illustrated in the above-mentioned alternative embodiment. On the other hand, the rods may instead extend for connection to the cylinders of the other set so as to transmit the forces through said last-mentioned cylinders to one platen, as illustrated in the first-mentioned embodiment. In this latter case, load plates are connected to the open ends of cylindrical bodies forming the inner, closed ends of the first and second sets of cylinders, and the rods engage such load plates so as to distribute the load substantially evenly between the various rams and cylinders.

In the drawings, wherein like reference characters are designated by like parts:

FIG. 1 is a perspective view of a hydraulic press having fixed platens at its upper and lower ends, a movable platen intermediate the fixed platens, and hydraulic rams arranged between the upper fixed platen and the movable platen in accordance with one illustrated embodiment of the present invention;

FIG. 2 is a vertical, sectional view of the rams in retracted positions, and as seen along broken line 22 of FIG. 4 through a lateral row of the upper set of cylinders;

FIG. 3 is a view similar to FIG. 2, but with the rams moved to extended positions so as to lower the movable platen relative to the fixed platen;

FIG. 4 is a horizontal sectional view of the ram arrangement of FIGS. 2 and 3, as seen along broken line 44 of FIG. 2, through the upper set of cylinders;

FIG. 5 is a horizontal sectional view similar to FIG. 4 but taken along broken line 5-5 of FIG. 2 through the lower set of cylinders;

FIG. 6 is a vertical sectional view of the rams in retracted position, and as seen along broken line 66 of FIG. 5 through a lateral row of the lower set of cylinders FIG. 7 is a view similar to FIG. 6, but with the rams moved to extended positions;

FIG. 8 is a vertical sectional view taken along a diagonal through the ram arrangement, as seen along broken line 8-8 of FIG. 4; and

FIG. 9 is a partial vertical sectional view of a press having a ram arrangement constructed in accordance with another embodiment of the present invention, the rams being shown in solid lines in their retracted positions and in bro-ken lines in their extended positions.

With reference now to the details of the above-described drawings, and with particular reference to FIG. 1, the hydraulic press, which is indicated in its entirety by reference character 20, includes a frame 21 having uprights 21a connected at the upper and lower ends 21b and 210, respectively, of the frame so as to form a loop. The uprights as well as the lower end of the frame are supported on a massive concrete footing 22 disposed beneath fioor level 23-. The uprights 21a are made up of spaced-apart, laminated walls 24 which are interconnected by bolts 24a and held in fixed spaced relation by spacers (not shown) about the bolts.

An upper fixed platen 25 is supported by the frame beneath its upper end 21!), and a lower fixed platen 26 is supported by the lower end 210 of the frame near the floor level 23. An intermediate movable platen 27 is disposed between the fixed platens 25 and 26 for movement vertically therebetween. All of the platens are, of course, disposed within the loop between the uprights of the frame. The movable platen 27 is forced downwardly toward the lower fixed platen 26 by means of the hydraulic ram assembly disposed between the opposite faces of the movable platen and the upper fixed platen. Thus, the lower face of the movable platen 27 is moved toward the upper face of the lower fixed platen 26 to press a work piece supported above the platen 26. This work piece may be a forging contained in a die and moved onto the upper surface of the platen 26 by means of a slide 29. A die may be supported from the lower face of the movable platen 27 for cooperation with the lower die in producing the desired forging.

The movable platen 27 is guided in its vertical movement within the loop by connection to a pair of vertically reciprocable guide columns 31 on each of the front and back sides of the frame uprights. More particularly, each of the guide columns 31 has a lower end received within a guide cylinder 32 mounted on the frame adjacent the uprights 21. The lower end of each such cylinder is closed to form a pressure chamber (not shown) beneath the lower end of the guide column 31. Thus, with the guide column sealably slidable within the cylinder, pressure may be admitted to the chambers so as to raise the columns and thus the platen 27, or exhausted therefrom to permit the guide columns to be forced downwardly, in a manner to be described.

As well known in the art, these guide columns are primarily useful in raising the movable platen 27 toward the upper fixed platen 25 upon completion of a pressing operation. For purposes of stability, the ends of the guide columns 31 are guidably slidable within outwardly extending portions of the platens 25 and 26 on each of the front and rear sides of the frame. The corners of the movable platen 27 are provided with connectors 35 which fixedly connect to the guide columns 31.

In the embodiment of the invention shown in FIGS. 1 to 8, the ram assembly disposed intermediate the platens 25 and 27 comprises a first set of cylinders 36 on an upper level and extending downwardly from the inner face of platen 25, and a second set of cylinders 37 on a lower level and extending upwardly from the inner face of platen 27. A ram 38 is sealably slidable within each of the cylinders 36 of the upper set, and a ram 39 is sealably slidable within each cylinder 37 of the lower set. The axis of each of the cylinders is perpendicular to the platen face from which it extends, and inasmuch as the inner faces of the platens 25 and 27 are parallel, the axes of all the cylinders 36, 37 are parallel to one another.

As best shown in FIGS. 4 and 5, the cylinders 36 of the first set and the cylinders 37 of the second set are arranged in substantially parallel, longitudinally and laterally extending rows. Thus, as shown in FIG. 4, there are three longitudinally extending rows and five laterally extending rows of cylinders 36 of the first or upper set. On the other hand, as shown in FIG. 5, there are two longit'udinally extending rows and four laterally extending rows of cylinders 37 of the second or lower set. More particularly, the rows of cylinders of each set are parallel to and longitudinally and laterally offset or staggered, respectivey, with respect to the rows of the other set. Thus, as shown in the illustrated embodiment of this ram arrangement, each longitudinally extending row of cylinders 37 is disposed midway of adjacent longitudinally extending rows of cylinders 36, while each laterally extending row of cylinders 37 is disposed midway adjacent laterally extending rows of cylinders 36. With the cylinders being of equal diameter and the longitudinally and laterally extending rows of both sets of cylinders arranged perpendicular to one another, as shown, the axes of the cylinders of each set lie in the same plane with the axes of cylinders of the other set as viewed along diagonal planes through such rows, so that each cylinder of each set is diagonally opposed to at least one cylinder of the other set.

In the embodiment of FIGS. 1 to 8, a first load plate 40 is connected to the open outer ends of individual cylindrical bodies forming the inner ends of cylinders 36, and a second load plate 41 is connected to the open outer ends of individual cylindrical bodies forming the inner ends of cylinders 37. More particularly, the load plates are secured to the ends of the respectivevcylindrical bodies by bolts or the like (not shown) and have openings therein which form the outer ends of such cylinders and carry seal rings 40a and 41a for sealing with respect to the rams slidable therein. Thus, upon the introduction of hydraulic fluid into each cylinder on the inner end of the ram slidable therein, the rams are urged from the retracted positions of FIGS. 2, 6 and *8 to the extended positions of FIGS. 3 and 7. Inasmuch as the open ends of the upper and lower sets of cylinders face one another, the rams move toward the lower rams as they move from retracted to extended positions. As shown in FIGS. 3 and 7, in their extended positions, the inner ends of the rams are substantially adjacent the inner sides of the load plates so that the stroke of each ram is approximately the length of each cylinder.

A cylindrical rod or post 42 extends axially downwardly from the lower end of each of the rams 38 and into engagement with the upper side of second load plate 41. A similar rod or post 43 extends axially upwardly from the outer end of each ram 39 and into engagement with the lower side of the first load plate 40. In this manner, the force developed in each of the cylinders 38, upon introduction of hydraulic fluid thereto, is transmitted through the rams 38, the rods 42, load plate 41, and the cylindrical bodies of the cylinders 37 to the movable platen 27. On the other hand, the force developed in the cylinders 37 of the second set is transmitted through the rams 39, the rods 43, the load plate 40, and the cylindrical bodies of the cylinders 36 to the fixed platen 25.

As illustrated, the rods are of lesser diameter than the rams so that the rams in the cylinders of each set are able to move past the rods for transmitting the force developed in the cylinders of the other set, as the rams are moved from retracted to extended positions. That is, rams 38 are able to move downwardly past the stationary rods 43, and the stationary rams 39 move relatively past the rods 42 as the latter are lowered with rams 38. Thus, as will be apparent from FIG. 8, this ram arrangement enables the axis of each ram in the cylinders of each set to be spaced from the axis of each ram in diagonally opposed cylinders of the other set by a distance less than the sum of the radii of such rams. That is, each ram in one set will overlap rams in cylinders of the other set in rows which are alternately adjacent to the row in which the rams of the one set is disposed. As a more specific example, each ram 39 in the cylinders 37 of the lower set overlap four rams 38 of the upper set.

In the preferred ram arrangement, as illustrated in the drawings, the cylinders of each set are tangent to two adjacent cylinders of the same set. Although each rod extending from each ram of the cylinders of each set is shown to be of such diameter as to be spaced a substantial distance from rams of the diagonally adjacent cylinders of the other set, as such rods and rams move past one another, they may in fact be of such diameter as to be substantially tangent to such rams as they move one another. This could be of advantage, for example, in the event a rod of greater cross-section were needed in order to transmit the forces developed in the cylinders.

In operation of the press, and assuming that the rams are retracted and the movable platen 27 raised to the position of FIGS. 2, 6 and 8, hydraulic fluid within the cylinders 32 beneath the lower ends of the columns 31 is relieved, and hydraulic fluid is introduced into the cylinders 36 and 37 so as to urge the rams toward extended positions and thereby move the platen 27 downwardly toward the work piece. As previously mentioned, the die on the lower face of the platen 27 ordinarily will engage the work piece and complete its work thereon prior to the rams reaching their fully extended positions.

When the desired press has been imposed on the work beneath the platen 27, hydraulic fluid within the cylinders 36 and 37 is relieved, and hydraulic fluid is readmitted to the pressure chambers within the lower ends of the cylinders 32 so as to lift the columns 31. This, of course, lifts the platen 27 through the connectors 35 so as to return the rams to their retracted positions, as shown in FIGS. 2, 6 and 8.

As shown in the drawings, each of the cylinders 36 of the upper set has its upper end located within an annular recess on the inner face of platen 25 so as to locate it against sidewise displacement. Similarly, each of the cylinders 37 of the second set has its lower end located within an annular recess on the inner face of platen 27.

Preferably, the means for supplying hydraulic fluid to each of the cylinders of the first and second sets comprises a manifold disposed entirely Within the upper fixed platen 25, thereby simplifying construction of the press. Thus, as shown in FIGS. 2, 3, 6, 7 and 8, flow passages 45 extend longitudinally through the platen 25 for connection with one another by means of laterally extending passages (not shown). The outermost and middle passages 45 connect with the cylinders 36 of the first set by means of vertically extending passages 45a, as shown in each of FIGS. 2, 3 and 8. The remaining passages 45, on the other hand, are connected with the cylinders 36 beneath the rams 39 in the manner illustrated in FIGS. 6, 7 and 8. Thus, vertically extending passages 45b connect such longitudinally extending passages with conduits 46 which extend parallel to and between adjacent cylinders 36. The lower ends of the conduits 46 are in turn connected with passages 47 through the rod 43, and the lower ends of the passages 47 connect with passages 48 through the rams 39. Thus, as will be apparent from FIG. 6, there is a continuous flow passage for hydraulic fluid between alternate longitudinally extending passages 45 and the cylinders 37 beneath the rams 39. As will be apparent from FIGS. 4 and 8, the conduits 46 may also be of larger diameter, at least to the extent of being substantially tangent to the cylinders 36 between which they are disposed.

The alternative ram arrangement disposed between.the fixed and movable platens 25' and 27', respectively, of the press partially shown in FIG. 9 differs from that of FIGS. 1 to 8 in that the open end of each of the cylinders 37' of the lower set faces in the same direction as the open end of each of the cylinders 36 of the upper set. That is, while the cylinders 36' extend downwardly from the lower face of fixed platen 25', the cylinders 37 extend downwardly from points intermediate the platens. More particularly, and as will be described to follow, the cylinders 37' are fixed with respect to fixed platen 25, so that the rams 39' are moved downwardly from the retracted position shown in solid lines in FIG. 9 to the extended position shown in broken lines thereof, whereby the platen 27 is moved downwardly away from the lower open ends of such cylinders. At the same time, of course, the rams 38' in the upper set of cylinders 36 are similar to the rams 38 in the first set of cylinders in the embodiment of FIGS. 1 to 8, moved downwardly within the cylinders 36' from the retracted solid line position of FIG. 9 to the extended broken line position thereof.

As shown in FIG. 9, rods 42 extend axially downwardly from the outer ends of rams 38' for transmitting the force developed in the cylinders 36' to the platen 27', and rods 43' extend upwardly from the closed upper ends of cylinders 37 for transmitting the force developed in them to the platen 25. The embodiment of FIG. 9 also differs from the previously described embodiment in that these rods transmit force in each set of the cylinders directly to the platens, rather than through load plates and the other set of cylinders. Thus, as shown in FIG. 9, each rod 42 extends past the cylinders 37' and into direct engagement with the inner face of the platen 27, while each rod 43' extends past the cylinders 36' and into direct engagement with the inner face of the platen 25'. More especially, these rods are shown to be tangent to such cylinders.

In this embodiment, with the rams in their solid line retracted positions, the oppositely facing outer ends of the cylinders of the first and second sets are spaced apart a distance at least approximately equal to the stroke of the rams from retracted to extended positions. Thus, each rod is of a length equal to approximately two strokes plus the distances by which the rams remain within their cylinders in their fully extended positions. Seals 40a and 41a are carried within the cylinders near their open ends for sealing about the slidable rams.

As in the case of the embodiment of FIGS. 1 to 8, hydraulic fluid is introduced into the cylinders of both sets through a manifolding disposed entirely within the upper fixed platen 25' and comprising longitudinally extending passages 45' interconnected to one another by laterally extending passages (not shown). Each passage 45 above each cylinder 36' is connected to each of them by means of a vertically extending passage 45a. Each passage 45' above a cylinder 37' is connected thereto by means of vertically extending passage 45b. This in turn connects at its lower end with passages 50 extending entirely through the rod 43 and into the upper end of the cylinder 37' by means of hole 51 therein.

Obviously, the upper and lower sets of cylinders and rams shown in FIG. 9 may be arranged in the manner illustrated in connection with FIGS. 1 to 8. As shown in FIG. 9, the rods 42' and 43' are of considerably lesser diameter than the rams 38 and cylinders 37 from which they extend, and the rams in the two sets of cylinders overlap one another. Thus, in the diagonally arranged sectional view of FIG. 9, the axes of the rams 38' and 39' are shown spaced apart a distance less than the sum of their radii.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. A hydraulic press comprising a frame, a first platen fixed to the frame, a second platen mounted on the frame for movement toward and away from the first platen, first and second sets of cylinders of equal inner diameter disposed on different levels between the inner faces of the platens, the cylinders in each set being perpendicular to the inner platen faces and arranged with their axes lying in substantially parallel, longitudinally and laterally extending planes, a ram sealably slidable Within each cylinder, means for introducing hydraulic fiuid into each cylinder so as to move the ram therein from a retracted to an extended position with respect to the cylinder, the planes in which the cylinders of each set are arranged being parallel to and laterally and longitudinally offset, respectively, with respect to the adjacent planes in which the other set are arranged by a distance less than the inner diameter of each cylinder, and means including rods for transmitting the force developed in the cylinders of the first set to one of said platens and the force developed in the cylinders of the second set to the other platen, the outer ends of the cylinders in one set being spaced from the outer ends of the cylinders of the other set a distance at least equal to and not substantially greater than the stroke of each ram from retracted to extended position when said rams are in retracted positions, and each said rod being coaxial with the cylinder in which the force it transmits is developed and having an outer diameter which is smaller than the distance between the axis of a cylinder in one set and the axis of an adjacent cylinder of the other set, whereby said rams and rods move in side-by-side relation as said rams are moved to extended positions so as to move said second platen away from said first platen.

Z. A hydraulic press of the character defined in claim 1, wherein adjacent cylinders in each row of each set of cylinders are substantially tangent to one another.

3. For use in a hydraulic press, apparatus comprising a pair of oppositely facing platens which are relatively movable toward and away from one another, first and second cylinders disposed on different levels between the inner faces of the platens and with their axes perpendicular to said faces and parallel to one another and spaced apart a distance less than the sum of their inner radii, a ram sealably reciprocable within each cylinder, means for introducing hydraulic fluid into each cylinder so as to move the ram therein from a retracted to an extended position with respect to the cylinder, and means including rods for transmitting the force developed in the first cylinder to one of said platens and the force developed in the second cylinder to the other platen, the outer ends of the cylinders being spaced from one another a distance at least equal to and not substantially greater than the stroke of each ram from retracted to extended position, when said rams are retracted, each said rod being coaxial with the cylinder in which the force it transmits is developed and having an outer diameter which is smaller than the distance between the axes of said cylinders, whereby said rams and rods move in side-by-side relation as said rods are extended so as to move said platens relatively away from one another.

4. Apparatus of the character defined in claim 3, wherein the open ends of both cylinders face toward one platen.

5. Apparatus of the character defined in claim 3, wherein the first cylinder extends from one platen, and the second cylinder extends from the other platen.

6. Apparatus of the character defined in claim 3, wherein each rod extends past the other cylinder.

7. Apparatus of the character defined in claim 3, Wherein each rod is operatively connected to the other cylinder for transmitting said force through said other cylinder to one of the platens.

8. For use in a hydraulic press, apparatus comprising a pair of oppositely facing platens which are relatively movable toward and away from one another, first and second sets of cylinders of equal inner diameter disposed on different levels between the inner faces of said platens and with their axes perpendicular to said inner faces, the cylinders in each set being arranged with their axes lying in substantially parallel, longitudinally and laterally extending planes, the laterally extending planes being perpendicular to the longitudinally extending planes, and the planes in which the cylinders of each set are arranged being parallel to and laterally and longitudinally offset, respectively, with respect to the adjacent planes in which the cylinders of the other set are arranged by a distance less than the inner diameter of each cylinder, a ram sealably reciprocable within each cylinder, means for introducing hydraulic fluid into each cylinder so as to move the ram therein from a retracted position to an extended position with respect to the cylinder, and means including rods for transmitting the force developed in the cylinders of the first set to one of said platens and the force developed in the cylinders of the second set to the other of said platens, the outer ends of the cylinders of the two sets being spaced from one another a distance at least as great as and not substantially greater than the stroke of each ram from retracted to extended position, when said rams are retracted, and each rod being coaxial with the cylinder in which the force it transmits is developed and having an outer diameter which is smaller than the distance between the axis of a cylinder in one set and the axis of an adjacent cylinder in the other set, whereby said rams and rods move in side-by-side relation and said rams are extended so as to move the platens relatively away from one another.

9. For use in a hydraulic press, apparatus comprising a pair of oppositely facing platens which are relatively movable toward and away from one another, first and second sets of cylinders disposed on different levels between the inner faces of said platens and with their axes perpendicular to said inner faces, the cylinders in each set being arranged with their axes lying in substantially parallel, longitudinally and laterally extending planes, the laterally extending planes being perpendicular to the longitudinally extending planes and the planes in which the cylinders of each set are arranged being parallel to and laterally and longitudinally offset, respectively, with respect to the adjacent planes in which the cylinders of the other set are arranged, a ram sealably reciprocable within each cylinder, means for introducing hydraulic fluid into each cylinder so as to move the ram therein from a retracted position to an extended position with respect to the cylinder, means for transmitting the force developed in the cylinders of the first set to one of said platens and the force developed in the cylinders of the second set to the other of said platens, the outer ends of the cylinders of the two sets being spaced from one another a distance at least as great as the stroke of each ram from retracted to extended position, when said rams are retracted, whereby said rams may be extended so as to move the platens relatively away from one another, each such cylinder including an individual cylindrical body, a first load plate connected to the outer ends of each such body of the cylinders of the first set, and a second load plate connected to the outer ends of each such body of the cylinders of the second set, the means for transmitting the forces developed in the cylinders of the first set engaging a second load plate, and the means for transmitting the forces developed in the cylinders of the second set engaging the first load plate, so as to trans mit said forces through said load plates and cylindrical bodies to said platens.

10. Apparatus of the character defined in claim 8, wherein adjacent cylinders in each row of each set are substantially tangent to one another.

References Cited UNITED STATES PATENTS 2,197,441 4/ 1940 Perony 72-453 3,205,749 9/ 1965 Schenk 72453 3,274,819 9/1966 Knowles 72-453 3,333,457 8/1967 Allen 72453 3,338,573 8/1967 Lukas -269 CHARLES W. LANHAM, Primary Examiner G. P. CROSBY, Assistant Examiner US. Cl. X.R. 72-455; 100-269 

